Hana ʻana o ka alumini sulfate-maka mea, alumini trihydrate

ʻO ka aluminium sulfate (Al2(SO4)3), i kapa pinepine ʻia he alum, ua hana ʻia ma ke ʻano he mau kristal keʻokeʻo ʻaʻole hiki ke ʻā a hoʻoheheʻe ʻia i ka wai. ʻO kēia hydrate maloʻo (Al2(SO4)3.14H2O) he 17% Al2O3 a kūʻai ʻia aku hoʻi ma ke ʻano he 47% w/w aluminium sulfate solution ʻo ia hoʻi he 8% Al2O3. Kūʻai ʻia aku hoʻi ma ke ʻano paʻa e like me ke kibbled, wili ʻia a lepo paha.

Hoʻohana nui ʻia ka aluminium sulfate, ʻo Al2(SO4)3, e ka ʻoihana. ʻO kāna mau noi maʻamau i ka ʻoihana pulp a me ka pepa a me ka hoʻomaʻemaʻe ʻana i ka wai. Ua hoʻohana ʻia ka aluminium sulfate e ke kanaka mai ka makahiki 2000 BC, i ka wā i hoʻohana ai ka poʻe ʻAigupita i ka alum mineral ma ke ʻano he mordant i ka hoʻoluʻu ʻana. Ua hoʻohana lōʻihi ʻia ia i ka nui o ka pepa e hoʻomaikaʻi i ke kūpaʻa a me ka ʻae ʻana i ka ʻīnika a me ka mālama ʻana i ka wai e hoʻomālamalama i ka wai. ʻO nā hoʻohana ʻē aʻe no ka alum e komo pū me ka mālama ʻana i ka wai ʻino, ma ke ʻano he mea pale wai a me ka mea hoʻolalelale i ka sima, ma ke ʻano he mea hoʻomālamalama no nā momona a me nā aila a ma ke ʻano he mea hoʻopū i nā huʻa ahi.

Hana ʻia ka alum (e like me ka mea i kapa pinepine ʻia ai ka aluminium sulfate) ma kahi kaʻina hana ʻelua-ʻanuʻu maʻalahi mai ka aluminium trihydrate a me ka sulfuric acid e like me ka hopena penei:

2Al(OH)3 + 3H2SO4 + 8H2O → Al2(SO4)3 .14H2O ∆fH = -156 kJ mol-1

ʻO ka hana mua e pili ana i ke kāwili ʻana i nā mea hoʻohui i loko o kahi reactor, a ʻo ka lua ke kaʻina hana o ka wili ʻana i ka mea e hana i nā ʻano like ʻole o ka alum paʻa i kūʻai ʻia aku.

Nā mea maka

Hoʻomaʻemaʻe ʻia ka aluminium trihydrate mai ka bauxite. Loaʻa nā waihona bauxite kalepa (30-75% Al2O3) ma Australia, Jamaica, Farani, Guyana, Guinea, USA a me Brazil. Hoʻoheheʻe ʻia ka hao bauxite i loko o ka soda caustic ikaika e hana i ka sodium aluminate. A laila hoʻoheheʻe ʻia ka aluminium trihydrate e ka neutralization (maʻamau me ke kalapona dioxide) a i ʻole ma ka autoprecipitation (ke kaʻina hana Bayer). ʻO ka mea maka ʻē aʻe, ka waikawa sulfuric, hana ʻia no ka hana superphosphate ma Farmers Fertiliser Ltd. Hōʻea ka waikawa ma ka moku tanker alanui a hoʻopili ʻia i loko o nā pahu mālama.